The prior art discloses open-ended containers for holding a volatile material which utilizes a plurality of layers to seal the container. Generally, one layer of material is permeable and permanently secured to the open end of the container and a second layer of material is impermeable and removable for when the container is utilized to dispense the volatile material. Thus, U.S. Pat. No. 4,157,787 discloses an air freshener dispenser having a container with an opening at its upper end surrounded by a peripheral flange. The open upper end of the container is covered with a porous layer secured to the upper surface of the flange and a removable nonporous layer which is removably secured to the upper surface of the porous layer. U.S. Pat. No. 4,145,001 discloses a package utilizing a multi-layer sealing laminate. The inner layer is permeable to a volatile material held within the package and the outer layer is impermeable. The outer layer is removed to expose the inner layer when the package is to be used.
The prior art also discloses containers useful for various purposes which have one or more upwardly directed projections in the base of the container. The projections, however, are not used in conjunction with a container seal. Thus, U.S. Pat. No. Des. 135,588 discloses a ration container comprising a tray with upstanding sidewalls having a ridge extending upward from the bottom surface of the tray to a level just below the upper edge of the tray sidewalls. U.S. Pat. No. 2,422,814 discloses a stamp pad having a bottom container divided into a plurality of ink containing reservoirs. The reservoirs are separated by upstanding ridges. An absorbent pad exends across the top of the reservoirs. When ink is to be absorbed into the pad from the reservoirs, the pad is pressed downward until it contacts the reservoirs between the ridges. U.S. Pat. No. 3,221,971 discloses a packaging tray having a plurality of upwardly curving figures around the edge of the tray and a rib means provided on the bottom of the tray. The rib means is disclosed as facilitating the placement of articles in the tray and ensuring that the articles remain properly positioned during transportation. While the packaging tray is disclosed for use with an overwrap, the rib does not extend upward above the articles held in the tray. U.S. Pat. No. 3,466,424 discloses a metallic cartridge for holding an evaporatable material. The cartridge has an opening in the central upper region of the cartridge. The cartridge additionally has a slightly raised portion in the bottom surface of the cartridge which reduces the amount of evaporatable material which can be disposed directly underneath the vapor exit port, provides for a hotter region in the area of the exit port, and prevents clogging of the openings in the exit port during vapor deposition.
Various containers are also disclosed in the prior art which utilize ribs and a container seal. However, the ribs and seal are not disclosed as operating in conjunction with each other. The ribs are solely related to the bottom structure of the containers and are utilized to provide strength, drainage or the like. For example, U.S. Pat. No. 4,055,672 discloses a package providing for a controlled atmospheric condition through the use of permeable and impermeable films and a package bottom wall containing downwardly extending grooves. The grooves provide a collection point for any fluid discharged from the material held within the package and also serve to enhance air circulation within the package once the outer impermeable layer is peeled away from the inner permeable layer.
The prior art also discloses various structures for electrically heated vapor dispensing apparatus which utilize containers or cartridges which are inserted into the apparatus and which hold a volatile material to be dispensed. Thus, U.S. Pat. No. 4,571,485 discloses an electrically heated aromatic generator utilizing a replaceable aroma cube which is insertable into a well in the generator. The cube is an open-ended chimney structure having a shallow box supported therein at its lower end by means of spider ribs which extend between the cube walls. A porous pad having good wicking properties is held within the box and is impregnated with a volatile aromatic liquid. The pad is covered with a wire or plastic net which is secured to the box to retain the pad therein. A peel-off cover can be placed over the net to prevent volatilization of the liquid during prolonged storage of the cube. U.S. Pat. No. 4,383,377 discloses a hot air hand dryer having a housing which includes a perforated container or cup for holding a vaporizable deodorizing material. The container or cup is screwed or snapped in place to the air dryer. The deodorizing material is in the form of a stick or cake which is placed in the container or cup through a slot in the container. U.S. Pat. No. 3,990,848 discloses a battery operated vapor dispensing device utilizing a cartridge for holding a vaporizable material. The cartridge includes a container having a number of holes in its top, bottom, and sides to facilitate the flow of air around a solid cylindrical block of vaporizable material which is held within the container. U.S. Pat. No. 4,629,604 discloses an aroma cartridge player wherein each cartridge holds a plurality of fragrances. The cartridge has a rectangular multi-sectioned framework. The cartridge is inserted into the cartridge player which utilizes heat to vaporize the volatile aromatic materials.
The prior art does not disclose the use of one or more free-standing ribs in conjunction with a flexible container seal to provide a tamper-resistant container. Further, the art does not disclose the use of such a container in combination with an electrically heated vapor dispensing apparatus.